1. Technical Field
The present invention relates to an apparatus for holding workpieces, more particularly to an apparatus for holding printed circuit boards, integrated circuit substrates, etc. during a packaging process.
2. Discussion of Related Art
Ball Grid Array (BGA) technology is widely used in packaging of integrated circuits. Generally, a BGA packaging process includes steps of: chip attaching, first plasma cleaning, wire bonding, second plasma cleaning, packaging, solder ball mounting, reflux welding, marking, slicing, and testing. Recently, with the developments in reducing size of integrated circuits, the solder balls are necessarily becoming smaller and smaller, resulting in the solder ball mounting step becoming more and more difficult. During the solder ball mounting step, misalignment of solder balls may occur.
In order to reuse the chip and the substrate of packages in which solder balls are misaligned, the packages must first be cleaned. Usually, the packages are manually cleaned one by one with a hot air gun, which is inefficient.
Therefore, there is a desire to develop a holder for holding the packages such that the packages can be cleaned in batches so as to improve an efficiency of the cleaning process.